text: /*
   * vim:ts=4:sw=4:expandtab
   *
   * i3 - an improved dynamic tiling window manager
   * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
   *
   * ipc.c: UNIX domain socket IPC (initialization, client handling, protocol).
   *
   */
  #include "all.h"
  
  #include "yajl_utils.h"
  
  #include <stdint.h>
  #include <sys/socket.h>
  #include <sys/un.h>
  #include <fcntl.h>
  #include <libgen.h>
  #include <ev.h>
  #include <yajl/yajl_gen.h>
  #include <yajl/yajl_parse.h>
  
  char *current_socketpath = NULL;
  
  TAILQ_HEAD(ipc_client_head, ipc_client)
  all_clients = TAILQ_HEAD_INITIALIZER(all_clients);
  
  /*
   * Puts the given socket file descriptor into non-blocking mode or dies if
   * setting O_NONBLOCK failed. Non-blocking sockets are a good idea for our
   * IPC model because we should by no means block the window manager.
   *
   */
  static void set_nonblock(int sockfd) {
      int flags = fcntl(sockfd, F_GETFL, 0);
      flags |= O_NONBLOCK;
      if (fcntl(sockfd, F_SETFL, flags) < 0)
          err(-1, "Could not set O_NONBLOCK");
  }
  
  /*
   * Given a message and a message type, create the corresponding header, merge it
   * with the message and append it to the given client's output buffer.
   *
   */
  static void append_payload(ipc_client *client, uint32_t message_type, const char *payload) {
      const size_t size = strlen(payload);
      const i3_ipc_header_t header = {
          .magic = {'i', '3', '-', 'i', 'p', 'c'},
          .size = size,
          .type = message_type};
      const size_t header_size = sizeof(i3_ipc_header_t);
      const size_t message_size = header_size + size;
  
      client->buffer = srealloc(client->buffer, client->buffer_size + message_size);
      memcpy(client->buffer + client->buffer_size, ((void *)&header), header_size);
      memcpy(client->buffer + client->buffer_size + header_size, payload, size);
      client->buffer_size += message_size;
  }
  
  static void free_ipc_client(ipc_client *client) {
      close(client->fd);
  
      ev_io_stop(main_loop, client->callback);
      FREE(client->callback);
      if (client->timeout) {
          ev_timer_stop(main_loop, client->timeout);
          FREE(client->timeout);
      }
  
      free(client->buffer);
  
      for (int i = 0; i < client->num_events; i++) {
          free(client->events[i]);
      }
      free(client->events);
      TAILQ_REMOVE(&all_clients, client, clients);
      free(client);
  }
  
  static void ipc_client_timeout(EV_P_ ev_timer *w, int revents);
  static void ipc_socket_writeable_cb(EV_P_ struct ev_io *w, int revents);
  
  static ev_tstamp kill_timeout = 10.0;
  
  void ipc_set_kill_timeout(ev_tstamp new) {
      kill_timeout = new;
  }
  
  /*
   * Try to write the contents of the pending buffer to the client's subscription
   * socket. Will set, reset or clear the timeout and io callbacks depending on
   * the result of the write operation.
   *
   */
  static void ipc_push_pending(ipc_client *client) {
      const ssize_t result = writeall_nonblock(client->fd, client->buffer, client->buffer_size);
      if (result < 0) {
          return;
      }
  
      if ((size_t)result == client->buffer_size) {
          /* Everything was written successfully: clear the timer and stop the io
           * callback. */
          FREE(client->buffer);
          client->buffer_size = 0;
          if (client->timeout) {
              ev_timer_stop(main_loop, client->timeout);
              FREE(client->timeout);
          }
          ev_io_stop(main_loop, client->callback);
          return;
      }
  
      /* Otherwise, make sure that the io callback is enabled and create a new
       * timer if needed. */
      ev_io_start(main_loop, client->callback);
  
      if (!client->timeout) {
          struct ev_timer *timeout = scalloc(1, sizeof(struct ev_timer));
          ev_timer_init(timeout, ipc_client_timeout, kill_timeout, 0.);
          timeout->data = client;
          client->timeout = timeout;
          ev_set_priority(timeout, EV_MINPRI);
          ev_timer_start(main_loop, client->timeout);
      } else if (result > 0) {
          /* Keep the old timeout when nothing is written. Otherwise, we would
           * keep a dead connection by continuously renewing its timeouts. */
          ev_timer_stop(main_loop, client->timeout);
          ev_timer_set(client->timeout, kill_timeout, 0.0);
          ev_timer_start(main_loop, client->timeout);
      }
      if (result == 0) {
          return;
      }
  
      /* Shift the buffer to the left and reduce the allocated space. */
      client->buffer_size -= (size_t)result;
      memmove(client->buffer, client->buffer + result, client->buffer_size);
      client->buffer = srealloc(client->buffer, client->buffer_size);
  }
  
  /*
   * Sends the specified event to all IPC clients which are currently connected
   * and subscribed to this kind of event.
   *
   */
  void ipc_send_event(const char *event, uint32_t message_type, const char *payload) {
      ipc_client *current;
      TAILQ_FOREACH(current, &all_clients, clients) {
          /* see if this client is interested in this event */
          bool interested = false;
          for (int i = 0; i < current->num_events; i++) {
              if (strcasecmp(current->events[i], event) != 0)
                  continue;
              interested = true;
              break;
          }
          if (!interested)
              continue;
  
          const bool push_now = (current->buffer_size == 0);
          append_payload(current, message_type, payload);
          if (push_now) {
              ipc_push_pending(current);
          }
      }
  }
  
  /*
   * For shutdown events, we send the reason for the shutdown.
   */
  static void ipc_send_shutdown_event(shutdown_reason_t reason) {
      yajl_gen gen = ygenalloc();
      y(map_open);
  
      ystr("change");
  
      if (reason == SHUTDOWN_REASON_RESTART) {
          ystr("restart");
      } else if (reason == SHUTDOWN_REASON_EXIT) {
          ystr("exit");
      }
  
      y(map_close);
  
      const unsigned char *payload;
      ylength length;
  
      y(get_buf, &payload, &length);
      ipc_send_event("shutdown", I3_IPC_EVENT_SHUTDOWN, (const char *)payload);
  
      y(free);
  }
  
  /*
   * Calls shutdown() on each socket and closes it. This function is to be called
   * when exiting or restarting only!
   *
   */
  void ipc_shutdown(shutdown_reason_t reason) {
      ipc_send_shutdown_event(reason);
  
      ipc_client *current;
      while (!TAILQ_EMPTY(&all_clients)) {
          current = TAILQ_FIRST(&all_clients);
          shutdown(current->fd, SHUT_RDWR);
          free_ipc_client(current);
      }
  }
  
  /*
   * Executes the command and returns whether it could be successfully parsed
   * or not (at the moment, always returns true).
   *
   */
  IPC_HANDLER(run_command) {
      /* To get a properly terminated buffer, we copy
       * message_size bytes out of the buffer */
      char *command = scalloc(message_size + 1, 1);
      strncpy(command, (const char *)message, message_size);
      LOG("IPC: received: *%s*\n", command);
      yajl_gen gen = yajl_gen_alloc(NULL);
  
      CommandResult *result = parse_command((const char *)command, gen);
      free(command);
  
      if (result->needs_tree_render)
          tree_render();
  
      command_result_free(result);
  
      const unsigned char *reply;
      ylength length;
      yajl_gen_get_buf(gen, &reply, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_COMMAND,
                       (const uint8_t *)reply);
  
      yajl_gen_free(gen);
  }
  
  static void dump_rect(yajl_gen gen, const char *name, Rect r) {
      ystr(name);
      y(map_open);
      ystr("x");
      y(integer, r.x);
      ystr("y");
      y(integer, r.y);
      ystr("width");
      y(integer, r.width);
      ystr("height");
      y(integer, r.height);
      y(map_close);
  }
  
  static void dump_gaps(yajl_gen gen, const char *name, gaps_t gaps) {
      ystr(name);
      y(map_open);
      ystr("inner");
      y(integer, gaps.inner);
  
      // TODO: the i3ipc Python modules recognize gaps, but only inner/outer
      // This is currently here to preserve compatibility with that
      ystr("outer");
      y(integer, gaps.top);
  
      ystr("top");
      y(integer, gaps.top);
      ystr("right");
      y(integer, gaps.right);
      ystr("bottom");
      y(integer, gaps.bottom);
      ystr("left");
      y(integer, gaps.left);
      y(map_close);
  }
  
  static void dump_event_state_mask(yajl_gen gen, Binding *bind) {
      y(array_open);
      for (int i = 0; i < 20; i++) {
          if (bind->event_state_mask & (1 << i)) {
              switch (1 << i) {
                  case XCB_KEY_BUT_MASK_SHIFT:
                      ystr("shift");
                      break;
                  case XCB_KEY_BUT_MASK_LOCK:
                      ystr("lock");
                      break;
                  case XCB_KEY_BUT_MASK_CONTROL:
                      ystr("ctrl");
                      break;
                  case XCB_KEY_BUT_MASK_MOD_1:
                      ystr("Mod1");
                      break;
                  case XCB_KEY_BUT_MASK_MOD_2:
                      ystr("Mod2");
                      break;
                  case XCB_KEY_BUT_MASK_MOD_3:
                      ystr("Mod3");
                      break;
                  case XCB_KEY_BUT_MASK_MOD_4:
                      ystr("Mod4");
                      break;
                  case XCB_KEY_BUT_MASK_MOD_5:
                      ystr("Mod5");
                      break;
                  case XCB_KEY_BUT_MASK_BUTTON_1:
                      ystr("Button1");
                      break;
                  case XCB_KEY_BUT_MASK_BUTTON_2:
                      ystr("Button2");
                      break;
                  case XCB_KEY_BUT_MASK_BUTTON_3:
                      ystr("Button3");
                      break;
                  case XCB_KEY_BUT_MASK_BUTTON_4:
                      ystr("Button4");
                      break;
                  case XCB_KEY_BUT_MASK_BUTTON_5:
                      ystr("Button5");
                      break;
                  case (I3_XKB_GROUP_MASK_1 << 16):
                      ystr("Group1");
                      break;
                  case (I3_XKB_GROUP_MASK_2 << 16):
                      ystr("Group2");
                      break;
                  case (I3_XKB_GROUP_MASK_3 << 16):
                      ystr("Group3");
                      break;
                  case (I3_XKB_GROUP_MASK_4 << 16):
                      ystr("Group4");
                      break;
              }
          }
      }
      y(array_close);
  }
  
  static void dump_binding(yajl_gen gen, Binding *bind) {
      y(map_open);
      ystr("input_code");
      y(integer, bind->keycode);
  
      ystr("input_type");
      ystr((const char *)(bind->input_type == B_KEYBOARD ? "keyboard" : "mouse"));
  
      ystr("symbol");
      if (bind->symbol == NULL)
          y(null);
      else
          ystr(bind->symbol);
  
      ystr("command");
      ystr(bind->command);
  
      // This key is only provided for compatibility, new programs should use
      // event_state_mask instead.
      ystr("mods");
      dump_event_state_mask(gen, bind);
  
      ystr("event_state_mask");
      dump_event_state_mask(gen, bind);
  
      y(map_close);
  }
  
  void dump_node(yajl_gen gen, struct Con *con, bool inplace_restart) {
      y(map_open);
      ystr("id");
      y(integer, (uintptr_t)con);
  
      ystr("type");
      switch (con->type) {
          case CT_ROOT:
              ystr("root");
              break;
          case CT_OUTPUT:
              ystr("output");
              break;
          case CT_CON:
              ystr("con");
              break;
          case CT_FLOATING_CON:
              ystr("floating_con");
              break;
          case CT_WORKSPACE:
              ystr("workspace");
              break;
          case CT_DOCKAREA:
              ystr("dockarea");
              break;
      }
  
      /* provided for backwards compatibility only. */
      ystr("orientation");
      if (!con_is_split(con))
          ystr("none");
      else {
          if (con_orientation(con) == HORIZ)
              ystr("horizontal");
          else
              ystr("vertical");
      }
  
      ystr("scratchpad_state");
      switch (con->scratchpad_state) {
          case SCRATCHPAD_NONE:
              ystr("none");
              break;
          case SCRATCHPAD_FRESH:
              ystr("fresh");
              break;
          case SCRATCHPAD_CHANGED:
              ystr("changed");
              break;
      }
  
      ystr("percent");
      if (con->percent == 0.0)
          y(null);
      else
          y(double, con->percent);
  
      ystr("urgent");
      y(bool, con->urgent);
  
      if (!TAILQ_EMPTY(&(con->marks_head))) {
          ystr("marks");
          y(array_open);
  
          mark_t *mark;
          TAILQ_FOREACH(mark, &(con->marks_head), marks) {
              ystr(mark->name);
          }
  
          y(array_close);
      }
  
      ystr("focused");
      y(bool, (con == focused));
  
      if (con->type != CT_ROOT && con->type != CT_OUTPUT) {
          ystr("output");
          ystr(con_get_output(con)->name);
      }
  
      ystr("layout");
      switch (con->layout) {
          case L_DEFAULT:
              DLOG("About to dump layout=default, this is a bug in the code.\n");
              assert(false);
              break;
          case L_SPLITV:
              ystr("splitv");
              break;
          case L_SPLITH:
              ystr("splith");
              break;
          case L_STACKED:
              ystr("stacked");
              break;
          case L_TABBED:
              ystr("tabbed");
              break;
          case L_DOCKAREA:
              ystr("dockarea");
              break;
          case L_OUTPUT:
              ystr("output");
              break;
      }
  
      ystr("workspace_layout");
      switch (con->workspace_layout) {
          case L_DEFAULT:
              ystr("default");
              break;
          case L_STACKED:
              ystr("stacked");
              break;
          case L_TABBED:
              ystr("tabbed");
              break;
          default:
              DLOG("About to dump workspace_layout=%d (none of default/stacked/tabbed), this is a bug.\n", con->workspace_layout);
              assert(false);
              break;
      }
  
      ystr("last_split_layout");
      switch (con->layout) {
          case L_SPLITV:
              ystr("splitv");
              break;
          default:
              ystr("splith");
              break;
      }
  
      ystr("border");
      switch (con->border_style) {
          case BS_NORMAL:
              ystr("normal");
              break;
          case BS_NONE:
              ystr("none");
              break;
          case BS_PIXEL:
              ystr("pixel");
              break;
      }
  
      ystr("current_border_width");
      y(integer, con->current_border_width);
  
      dump_rect(gen, "rect", con->rect);
      dump_rect(gen, "deco_rect", con->deco_rect);
      dump_rect(gen, "window_rect", con->window_rect);
      dump_rect(gen, "geometry", con->geometry);
  
      ystr("name");
      if (con->window && con->window->name)
          ystr(i3string_as_utf8(con->window->name));
      else if (con->name != NULL)
          ystr(con->name);
      else
          y(null);
  
      if (con->title_format != NULL) {
          ystr("title_format");
          ystr(con->title_format);
      }
  
      if (con->type == CT_WORKSPACE) {
          ystr("num");
          y(integer, con->num);
  
          dump_gaps(gen, "gaps", con->gaps);
      }
  
      ystr("window");
      if (con->window)
          y(integer, con->window->id);
      else
          y(null);
  
      if (con->window && !inplace_restart) {
          /* Window properties are useless to preserve when restarting because
           * they will be queried again anyway. However, for i3-save-tree(1),
           * they are very useful and save i3-save-tree dealing with X11. */
          ystr("window_properties");
          y(map_open);
  
  #define DUMP_PROPERTY(key, prop_name)         \
      do {                                      \
          if (con->window->prop_name != NULL) { \
              ystr(key);                        \
              ystr(con->window->prop_name);     \
          }                                     \
      } while (0)
  
          DUMP_PROPERTY("class", class_class);
          DUMP_PROPERTY("instance", class_instance);
          DUMP_PROPERTY("window_role", role);
  
          if (con->window->name != NULL) {
              ystr("title");
              ystr(i3string_as_utf8(con->window->name));
          }
  
          ystr("transient_for");
          if (con->window->transient_for == XCB_NONE)
              y(null);
          else
              y(integer, con->window->transient_for);
  
          y(map_close);
      }
  
      ystr("nodes");
      y(array_open);
      Con *node;
      if (con->type != CT_DOCKAREA || !inplace_restart) {
          TAILQ_FOREACH(node, &(con->nodes_head), nodes) {
              dump_node(gen, node, inplace_restart);
          }
      }
      y(array_close);
  
      ystr("floating_nodes");
      y(array_open);
      TAILQ_FOREACH(node, &(con->floating_head), floating_windows) {
          dump_node(gen, node, inplace_restart);
      }
      y(array_close);
  
      ystr("focus");
      y(array_open);
      TAILQ_FOREACH(node, &(con->focus_head), focused) {
          y(integer, (uintptr_t)node);
      }
      y(array_close);
  
      ystr("fullscreen_mode");
      y(integer, con->fullscreen_mode);
  
      ystr("sticky");
      y(bool, con->sticky);
  
      ystr("floating");
      switch (con->floating) {
          case FLOATING_AUTO_OFF:
              ystr("auto_off");
              break;
          case FLOATING_AUTO_ON:
              ystr("auto_on");
              break;
          case FLOATING_USER_OFF:
              ystr("user_off");
              break;
          case FLOATING_USER_ON:
              ystr("user_on");
              break;
      }
  
      ystr("swallows");
      y(array_open);
      Match *match;
      TAILQ_FOREACH(match, &(con->swallow_head), matches) {
          /* We will generate a new restart_mode match specification after this
           * loop, so skip this one. */
          if (match->restart_mode)
              continue;
          y(map_open);
          if (match->dock != M_DONTCHECK) {
              ystr("dock");
              y(integer, match->dock);
              ystr("insert_where");
              y(integer, match->insert_where);
          }
  
  #define DUMP_REGEX(re_name)                \
      do {                                   \
          if (match->re_name != NULL) {      \
              ystr(#re_name);                \
              ystr(match->re_name->pattern); \
          }                                  \
      } while (0)
  
          DUMP_REGEX(class);
          DUMP_REGEX(instance);
          DUMP_REGEX(window_role);
          DUMP_REGEX(title);
  
  #undef DUMP_REGEX
          y(map_close);
      }
  
      if (inplace_restart) {
          if (con->window != NULL) {
              y(map_open);
              ystr("id");
              y(integer, con->window->id);
              ystr("restart_mode");
              y(bool, true);
              y(map_close);
          }
      }
      y(array_close);
  
      if (inplace_restart && con->window != NULL) {
          ystr("depth");
          y(integer, con->depth);
      }
  
      y(map_close);
  }
  
  static void dump_bar_bindings(yajl_gen gen, Barconfig *config) {
      if (TAILQ_EMPTY(&(config->bar_bindings)))
          return;
  
      ystr("bindings");
      y(array_open);
  
      struct Barbinding *current;
      TAILQ_FOREACH(current, &(config->bar_bindings), bindings) {
          y(map_open);
  
          ystr("input_code");
          y(integer, current->input_code);
          ystr("command");
          ystr(current->command);
          ystr("release");
          y(bool, current->release == B_UPON_KEYRELEASE);
  
          y(map_close);
      }
  
      y(array_close);
  }
  
  static char *canonicalize_output_name(char *name) {
      /* Do not canonicalize special output names. */
      if (strcasecmp(name, "primary") == 0) {
          return name;
      }
      Output *output = get_output_by_name(name, false);
      return output ? output_primary_name(output) : name;
  }
  
  static void dump_bar_config(yajl_gen gen, Barconfig *config) {
      y(map_open);
  
      ystr("id");
      ystr(config->id);
  
      if (config->num_outputs > 0) {
          ystr("outputs");
          y(array_open);
          for (int c = 0; c < config->num_outputs; c++) {
              /* Convert monitor names (RandR ≥ 1.5) or output names
               * (RandR < 1.5) into monitor names. This way, existing
               * configs which use output names transparently keep
               * working. */
              ystr(canonicalize_output_name(config->outputs[c]));
          }
          y(array_close);
      }
  
      if (!TAILQ_EMPTY(&(config->tray_outputs))) {
          ystr("tray_outputs");
          y(array_open);
  
          struct tray_output_t *tray_output;
          TAILQ_FOREACH(tray_output, &(config->tray_outputs), tray_outputs) {
              ystr(canonicalize_output_name(tray_output->output));
          }
  
          y(array_close);
      }
  
  #define YSTR_IF_SET(name)       \
      do {                        \
          if (config->name) {     \
              ystr(#name);        \
              ystr(config->name); \
          }                       \
      } while (0)
  
      ystr("tray_padding");
      y(integer, config->tray_padding);
  
      YSTR_IF_SET(socket_path);
  
      ystr("mode");
      switch (config->mode) {
          case M_HIDE:
              ystr("hide");
              break;
          case M_INVISIBLE:
              ystr("invisible");
              break;
          case M_DOCK:
          default:
              ystr("dock");
              break;
      }
  
      ystr("hidden_state");
      switch (config->hidden_state) {
          case S_SHOW:
              ystr("show");
              break;
          case S_HIDE:
          default:
              ystr("hide");
              break;
      }
  
      ystr("modifier");
      y(integer, config->modifier);
  
      dump_bar_bindings(gen, config);
  
      ystr("position");
      if (config->position == P_BOTTOM)
          ystr("bottom");
      else
          ystr("top");
  
      YSTR_IF_SET(status_command);
      YSTR_IF_SET(font);
  
      if (config->bar_height) {
          ystr("bar_height");
          y(integer, config->bar_height);
      }
  
      if (config->separator_symbol) {
          ystr("separator_symbol");
          ystr(config->separator_symbol);
      }
  
      ystr("workspace_buttons");
      y(bool, !config->hide_workspace_buttons);
  
      ystr("strip_workspace_numbers");
      y(bool, config->strip_workspace_numbers);
  
      ystr("strip_workspace_name");
      y(bool, config->strip_workspace_name);
  
      ystr("binding_mode_indicator");
      y(bool, !config->hide_binding_mode_indicator);
  
      ystr("verbose");
      y(bool, config->verbose);
  
  #undef YSTR_IF_SET
  #define YSTR_IF_SET(name)              \
      do {                               \
          if (config->colors.name) {     \
              ystr(#name);               \
              ystr(config->colors.name); \
          }                              \
      } while (0)
  
      ystr("colors");
      y(map_open);
      YSTR_IF_SET(background);
      YSTR_IF_SET(statusline);
      YSTR_IF_SET(separator);
      YSTR_IF_SET(focused_background);
      YSTR_IF_SET(focused_statusline);
      YSTR_IF_SET(focused_separator);
      YSTR_IF_SET(focused_workspace_border);
      YSTR_IF_SET(focused_workspace_bg);
      YSTR_IF_SET(focused_workspace_text);
      YSTR_IF_SET(active_workspace_border);
      YSTR_IF_SET(active_workspace_bg);
      YSTR_IF_SET(active_workspace_text);
      YSTR_IF_SET(inactive_workspace_border);
      YSTR_IF_SET(inactive_workspace_bg);
      YSTR_IF_SET(inactive_workspace_text);
      YSTR_IF_SET(urgent_workspace_border);
      YSTR_IF_SET(urgent_workspace_bg);
      YSTR_IF_SET(urgent_workspace_text);
      YSTR_IF_SET(binding_mode_border);
      YSTR_IF_SET(binding_mode_bg);
      YSTR_IF_SET(binding_mode_text);
      y(map_close);
  
      y(map_close);
  #undef YSTR_IF_SET
  }
  
  IPC_HANDLER(tree) {
      setlocale(LC_NUMERIC, "C");
      yajl_gen gen = ygenalloc();
      dump_node(gen, croot, false);
      setlocale(LC_NUMERIC, "");
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_TREE, payload);
      y(free);
  }
  
  /*
   * Formats the reply message for a GET_WORKSPACES request and sends it to the
   * client
   *
   */
  IPC_HANDLER(get_workspaces) {
      yajl_gen gen = ygenalloc();
      y(array_open);
  
      Con *focused_ws = con_get_workspace(focused);
  
      Con *output;
      TAILQ_FOREACH(output, &(croot->nodes_head), nodes) {
          if (con_is_internal(output))
              continue;
          Con *ws;
          TAILQ_FOREACH(ws, &(output_get_content(output)->nodes_head), nodes) {
              assert(ws->type == CT_WORKSPACE);
              y(map_open);
  
              ystr("num");
              y(integer, ws->num);
  
              ystr("name");
              ystr(ws->name);
  
              ystr("visible");
              y(bool, workspace_is_visible(ws));
  
              ystr("focused");
              y(bool, ws == focused_ws);
  
              ystr("rect");
              y(map_open);
              ystr("x");
              y(integer, ws->rect.x);
              ystr("y");
              y(integer, ws->rect.y);
              ystr("width");
              y(integer, ws->rect.width);
              ystr("height");
              y(integer, ws->rect.height);
              y(map_close);
  
              ystr("output");
              ystr(output->name);
  
              ystr("urgent");
              y(bool, ws->urgent);
  
              y(map_close);
          }
      }
  
      y(array_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_WORKSPACES, payload);
      y(free);
  }
  
  /*
   * Formats the reply message for a GET_OUTPUTS request and sends it to the
   * client
   *
   */
  IPC_HANDLER(get_outputs) {
      yajl_gen gen = ygenalloc();
      y(array_open);
  
      Output *output;
      TAILQ_FOREACH(output, &outputs, outputs) {
          y(map_open);
  
          ystr("name");
          ystr(output_primary_name(output));
  
          ystr("active");
          y(bool, output->active);
  
          ystr("primary");
          y(bool, output->primary);
  
          ystr("rect");
          y(map_open);
          ystr("x");
          y(integer, output->rect.x);
          ystr("y");
          y(integer, output->rect.y);
          ystr("width");
          y(integer, output->rect.width);
          ystr("height");
          y(integer, output->rect.height);
          y(map_close);
  
          ystr("current_workspace");
          Con *ws = NULL;
          if (output->con && (ws = con_get_fullscreen_con(output->con, CF_OUTPUT)))
              ystr(ws->name);
          else
              y(null);
  
          y(map_close);
      }
  
      y(array_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_OUTPUTS, payload);
      y(free);
  }
  
  /*
   * Formats the reply message for a GET_MARKS request and sends it to the
   * client
   *
   */
  IPC_HANDLER(get_marks) {
      yajl_gen gen = ygenalloc();
      y(array_open);
  
      Con *con;
      TAILQ_FOREACH(con, &all_cons, all_cons) {
          mark_t *mark;
          TAILQ_FOREACH(mark, &(con->marks_head), marks) {
              ystr(mark->name);
          }
      }
  
      y(array_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_MARKS, payload);
      y(free);
  }
  
  /*
   * Returns the version of i3
   *
   */
  IPC_HANDLER(get_version) {
      yajl_gen gen = ygenalloc();
      y(map_open);
  
      ystr("major");
      y(integer, MAJOR_VERSION);
  
      ystr("minor");
      y(integer, MINOR_VERSION);
  
      ystr("patch");
      y(integer, PATCH_VERSION);
  
      ystr("human_readable");
      ystr(i3_version);
  
      ystr("loaded_config_file_name");
      ystr(current_configpath);
  
      y(map_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_VERSION, payload);
      y(free);
  }
  
  /*
   * Formats the reply message for a GET_BAR_CONFIG request and sends it to the
   * client.
   *
   */
  IPC_HANDLER(get_bar_config) {
      yajl_gen gen = ygenalloc();
  
      /* If no ID was passed, we return a JSON array with all IDs */
      if (message_size == 0) {
          y(array_open);
          Barconfig *current;
          TAILQ_FOREACH(current, &barconfigs, configs) {
              ystr(current->id);
          }
          y(array_close);
  
          const unsigned char *payload;
          ylength length;
          y(get_buf, &payload, &length);
  
          ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BAR_CONFIG, payload);
          y(free);
          return;
      }
  
      /* To get a properly terminated buffer, we copy
       * message_size bytes out of the buffer */
      char *bar_id = NULL;
      sasprintf(&bar_id, "%.*s", message_size, message);
      LOG("IPC: looking for config for bar ID \"%s\"\n", bar_id);
      Barconfig *current, *config = NULL;
      TAILQ_FOREACH(current, &barconfigs, configs) {
          if (strcmp(current->id, bar_id) != 0)
              continue;
  
          config = current;
          break;
      }
      free(bar_id);
  
      if (!config) {
          /* If we did not find a config for the given ID, the reply will contain
           * a null 'id' field. */
          y(map_open);
  
          ystr("id");
          y(null);
  
          y(map_close);
      } else {
          dump_bar_config(gen, config);
      }
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BAR_CONFIG, payload);
      y(free);
  }
  
  /*
   * Returns a list of configured binding modes
   *
   */
  IPC_HANDLER(get_binding_modes) {
      yajl_gen gen = ygenalloc();
  
      y(array_open);
      struct Mode *mode;
      SLIST_FOREACH(mode, &modes, modes) {
          ystr(mode->name);
      }
      y(array_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BINDING_MODES, payload);
      y(free);
  }
  
  /*
   * Callback for the YAJL parser (will be called when a string is parsed).
   *
   */
  static int add_subscription(void *extra, const unsigned char *s,
                              ylength len) {
      ipc_client *client = extra;
  
      DLOG("should add subscription to extra %p, sub %.*s\n", client, (int)len, s);
      int event = client->num_events;
  
      client->num_events++;
      client->events = srealloc(client->events, client->num_events * sizeof(char *));
      /* We copy the string because it is not null-terminated and strndup()
       * is missing on some BSD systems */
      client->events[event] = scalloc(len + 1, 1);
      memcpy(client->events[event], s, len);
  
      DLOG("client is now subscribed to:\n");
      for (int i = 0; i < client->num_events; i++) {
          DLOG("event %s\n", client->events[i]);
      }
      DLOG("(done)\n");
  
      return 1;
  }
  
  /*
   * Subscribes this connection to the event types which were given as a JSON
   * serialized array in the payload field of the message.
   *
   */
  IPC_HANDLER(subscribe) {
      yajl_handle p;
      yajl_status stat;
      ipc_client *current, *client = NULL;
  
      /* Search the ipc_client structure for this connection */
      TAILQ_FOREACH(current, &all_clients, clients) {
          if (current->fd != fd)
              continue;
  
          client = current;
          break;
      }
  
      if (client == NULL) {
          ELOG("Could not find ipc_client data structure for fd %d\n", fd);
          return;
      }
  
      /* Setup the JSON parser */
      static yajl_callbacks callbacks = {
          .yajl_string = add_subscription,
      };
  
      p = yalloc(&callbacks, (void *)client);
      stat = yajl_parse(p, (const unsigned char *)message, message_size);
      if (stat != yajl_status_ok) {
          unsigned char *err;
          err = yajl_get_error(p, true, (const unsigned char *)message,
                               message_size);
          ELOG("YAJL parse error: %s\n", err);
          yajl_free_error(p, err);
  
          const char *reply = "{\"success\":false}";
          ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SUBSCRIBE, (const uint8_t *)reply);
          yajl_free(p);
          return;
      }
      yajl_free(p);
      const char *reply = "{\"success\":true}";
      ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SUBSCRIBE, (const uint8_t *)reply);
  
      if (client->first_tick_sent) {
          return;
      }
  
      bool is_tick = false;
      for (int i = 0; i < client->num_events; i++) {
          if (strcmp(client->events[i], "tick") == 0) {
              is_tick = true;
              break;
          }
      }
      if (!is_tick) {
          return;
      }
  
      client->first_tick_sent = true;
      const char *payload = "{\"first\":true,\"payload\":\"\"}";
      ipc_send_message(client->fd, strlen(payload), I3_IPC_EVENT_TICK, (const uint8_t *)payload);
  }
  
  /*
   * Returns the raw last loaded i3 configuration file contents.
   */
  IPC_HANDLER(get_config) {
      yajl_gen gen = ygenalloc();
  
      y(map_open);
  
      ystr("config");
      ystr(current_config);
  
      y(map_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_CONFIG, payload);
      y(free);
  }
  
  /*
   * Sends the tick event from the message payload to subscribers. Establishes a
   * synchronization point in event-related tests.
   */
  IPC_HANDLER(send_tick) {
      yajl_gen gen = ygenalloc();
  
      y(map_open);
  
      ystr("first");
      y(bool, false);
  
      ystr("payload");
      yajl_gen_string(gen, (unsigned char *)message, message_size);
  
      y(map_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_event("tick", I3_IPC_EVENT_TICK, (const char *)payload);
      y(free);
  
      const char *reply = "{\"success\":true}";
      ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_TICK, (const uint8_t *)reply);
      DLOG("Sent tick event\n");
  }
  
  struct sync_state {
      char *last_key;
      uint32_t rnd;
      xcb_window_t window;
  };
  
  static int _sync_json_key(void *extra, const unsigned char *val, size_t len) {
      struct sync_state *state = extra;
      FREE(state->last_key);
      state->last_key = scalloc(len + 1, 1);
      memcpy(state->last_key, val, len);
      return 1;
  }
  
  static int _sync_json_int(void *extra, long long val) {
      struct sync_state *state = extra;
      if (strcasecmp(state->last_key, "rnd") == 0) {
          state->rnd = val;
      } else if (strcasecmp(state->last_key, "window") == 0) {
          state->window = (xcb_window_t)val;
      }
      return 1;
  }
  
  IPC_HANDLER(sync) {
      yajl_handle p;
      yajl_status stat;
  
      /* Setup the JSON parser */
      static yajl_callbacks callbacks = {
          .yajl_map_key = _sync_json_key,
          .yajl_integer = _sync_json_int,
      };
  
      struct sync_state state;
      memset(&state, '\0', sizeof(struct sync_state));
      p = yalloc(&callbacks, (void *)&state);
      stat = yajl_parse(p, (const unsigned char *)message, message_size);
      FREE(state.last_key);
      if (stat != yajl_status_ok) {
          unsigned char *err;
          err = yajl_get_error(p, true, (const unsigned char *)message,
                               message_size);
          ELOG("YAJL parse error: %s\n", err);
          yajl_free_error(p, err);
  
          const char *reply = "{\"success\":false}";
          ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SYNC, (const uint8_t *)reply);
          yajl_free(p);
          return;
      }
      yajl_free(p);
  
      DLOG("received IPC sync request (rnd = %d, window = 0x%08x)\n", state.rnd, state.window);
      sync_respond(state.window, state.rnd);
      const char *reply = "{\"success\":true}";
      ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SYNC, (const uint8_t *)reply);
  }
  
  /* The index of each callback function corresponds to the numeric
   * value of the message type (see include/i3/ipc.h) */
  handler_t handlers[12] = {
      handle_run_command,
      handle_get_workspaces,
      handle_subscribe,
      handle_get_outputs,
      handle_tree,
      handle_get_marks,
      handle_get_bar_config,
      handle_get_version,
      handle_get_binding_modes,
      handle_get_config,
      handle_send_tick,
      handle_sync,
  };
  
  /*
   * Handler for activity on a client connection, receives a message from a
   * client.
   *
   * For now, the maximum message size is 2048. I’m not sure for what the
   * IPC interface will be used in the future, thus I’m not implementing a
   * mechanism for arbitrarily long messages, as it seems like overkill
   * at the moment.
   *
   */
  static void ipc_receive_message(EV_P_ struct ev_io *w, int revents) {
      uint32_t message_type;
      uint32_t message_length;
      uint8_t *message = NULL;
  
      int ret = ipc_recv_message(w->fd, &message_type, &message_length, &message);
      /* EOF or other error */
      if (ret < 0) {
          /* Was this a spurious read? See ev(3) */
          if (ret == -1 && errno == EAGAIN) {
              FREE(message);
              return;
          }
  
          /* If not, there was some kind of error. We don’t bother and close the
           * connection. Delete the client from the list of clients. */
          bool closed = false;
          ipc_client *current;
          TAILQ_FOREACH(current, &all_clients, clients) {
              if (current->fd != w->fd)
                  continue;
  
              free_ipc_client(current);
              closed = true;
              break;
          }
          if (!closed) {
              close(w->fd);
          }
  
          ev_io_stop(EV_A_ w);
          free(w);
          FREE(message);
  
          DLOG("IPC: client disconnected\n");
          return;
      }
  
      if (message_type >= (sizeof(handlers) / sizeof(handler_t)))
          DLOG("Unhandled message type: %d\n", message_type);
      else {
          handler_t h = handlers[message_type];
          h(w->fd, message, 0, message_length, message_type);
      }
  
      FREE(message);
  }
  
  static void ipc_client_timeout(EV_P_ ev_timer *w, int revents) {
      /* No need to be polite and check for writeability, the other callback would
       * have been called by now. */
      ipc_client *client = (ipc_client *)w->data;
  
      char *cmdline = NULL;
  #if defined(__linux__) && defined(SO_PEERCRED)
      struct ucred peercred;
      socklen_t so_len = sizeof(peercred);
      if (getsockopt(client->fd, SOL_SOCKET, SO_PEERCRED, &peercred, &so_len) != 0) {
          goto end;
      }
      char *exepath;
      sasprintf(&exepath, "/proc/%d/cmdline", peercred.pid);
  
      int fd = open(exepath, O_RDONLY);
      free(exepath);
      if (fd == -1) {
          goto end;
      }
      char buf[512] = {'\0'}; /* cut off cmdline for the error message. */
      const ssize_t n = read(fd, buf, sizeof(buf));
      close(fd);
      if (n < 0) {
          goto end;
      }
      for (char *walk = buf; walk < buf + n - 1; walk++) {
          if (*walk == '\0') {
              *walk = ' ';
          }
      }
      cmdline = buf;
  
      if (cmdline) {
          ELOG("client %p with pid %d and cmdline '%s' on fd %d timed out, killing\n", client, peercred.pid, cmdline, client->fd);
      }
  
  end:
  #endif
      if (!cmdline) {
          ELOG("client %p on fd %d timed out, killing\n", client, client->fd);
      }
  
      free_ipc_client(client);
  }
  
  static void ipc_socket_writeable_cb(EV_P_ ev_io *w, int revents) {
      DLOG("fd %d writeable\n", w->fd);
      ipc_client *client = (ipc_client *)w->data;
  
      /* If this callback is called then there should be a corresponding active
       * timer. */
      assert(client->timeout != NULL);
      ipc_push_pending(client);
  }
  
  /*
   * Handler for activity on the listening socket, meaning that a new client
   * has just connected and we should accept() him. Sets up the event handler
   * for activity on the new connection and inserts the file descriptor into
   * the list of clients.
   *
   */
  void ipc_new_client(EV_P_ struct ev_io *w, int revents) {
      struct sockaddr_un peer;
      socklen_t len = sizeof(struct sockaddr_un);
      int client;
      if ((client = accept(w->fd, (struct sockaddr *)&peer, &len)) < 0) {
          if (errno == EINTR)
              return;
          else
              perror("accept()");
          return;
      }
  
      /* Close this file descriptor on exec() */
      (void)fcntl(client, F_SETFD, FD_CLOEXEC);
  
      set_nonblock(client);
  
      struct ev_io *package = scalloc(1, sizeof(struct ev_io));
      ev_io_init(package, ipc_receive_message, client, EV_READ);
      ev_io_start(EV_A_ package);
  
      ipc_client *new = scalloc(1, sizeof(ipc_client));
  
      package = scalloc(1, sizeof(struct ev_io));
      package->data = new;
      ev_io_init(package, ipc_socket_writeable_cb, client, EV_WRITE);
  
      DLOG("IPC: new client connected on fd %d\n", w->fd);
  
      new->fd = client;
      new->callback = package;
  
      TAILQ_INSERT_TAIL(&all_clients, new, clients);
  }
  
  /*
   * Creates the UNIX domain socket at the given path, sets it to non-blocking
   * mode, bind()s and listen()s on it.
   *
   */
  int ipc_create_socket(const char *filename) {
      int sockfd;
  
      FREE(current_socketpath);
  
      char *resolved = resolve_tilde(filename);
      DLOG("Creating IPC-socket at %s\n", resolved);
      char *copy = sstrdup(resolved);
      const char *dir = dirname(copy);
      if (!path_exists(dir))
          mkdirp(dir, DEFAULT_DIR_MODE);
      free(copy);
  
      /* Unlink the unix domain socket before */
      unlink(resolved);
  
      if ((sockfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) {
          perror("socket()");
          free(resolved);
          return -1;
      }
  
      (void)fcntl(sockfd, F_SETFD, FD_CLOEXEC);
  
      struct sockaddr_un addr;
      memset(&addr, 0, sizeof(struct sockaddr_un));
      addr.sun_family = AF_LOCAL;
      strncpy(addr.sun_path, resolved, sizeof(addr.sun_path) - 1);
      if (bind(sockfd, (struct sockaddr *)&addr, sizeof(struct sockaddr_un)) < 0) {
          perror("bind()");
          free(resolved);
          return -1;
      }
  
      set_nonblock(sockfd);
  
      if (listen(sockfd, 5) < 0) {
          perror("listen()");
          free(resolved);
          return -1;
      }
  
      current_socketpath = resolved;
      return sockfd;
  }
  
  /*
   * Generates a json workspace event. Returns a dynamically allocated yajl
   * generator. Free with yajl_gen_free().
   */
  yajl_gen ipc_marshal_workspace_event(const char *change, Con *current, Con *old) {
      setlocale(LC_NUMERIC, "C");
      yajl_gen gen = ygenalloc();
  
      y(map_open);
  
      ystr("change");
      ystr(change);
  
      ystr("current");
      if (current == NULL)
          y(null);
      else
          dump_node(gen, current, false);
  
      ystr("old");
      if (old == NULL)
          y(null);
      else
          dump_node(gen, old, false);
  
      y(map_close);
  
      setlocale(LC_NUMERIC, "");
  
      return gen;
  }
  
  /*
   * For the workspace events we send, along with the usual "change" field, also
   * the workspace container in "current". For focus events, we send the
   * previously focused workspace in "old".
   */
  void ipc_send_workspace_event(const char *change, Con *current, Con *old) {
      yajl_gen gen = ipc_marshal_workspace_event(change, current, old);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_event("workspace", I3_IPC_EVENT_WORKSPACE, (const char *)payload);
  
      y(free);
  }
  
  /*
   * For the window events we send, along the usual "change" field,
   * also the window container, in "container".
   */
  void ipc_send_window_event(const char *property, Con *con) {
      DLOG("Issue IPC window %s event (con = %p, window = 0x%08x)\n",
           property, con, (con->window ? con->window->id : XCB_WINDOW_NONE));
  
      setlocale(LC_NUMERIC, "C");
      yajl_gen gen = ygenalloc();
  
      y(map_open);
  
      ystr("change");
      ystr(property);
  
      ystr("container");
      dump_node(gen, con, false);
  
      y(map_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_event("window", I3_IPC_EVENT_WINDOW, (const char *)payload);
      y(free);
      setlocale(LC_NUMERIC, "");
  }
  
  /*
   * For the barconfig update events, we send the serialized barconfig.
   */
  void ipc_send_barconfig_update_event(Barconfig *barconfig) {
      DLOG("Issue barconfig_update event for id = %s\n", barconfig->id);
      setlocale(LC_NUMERIC, "C");
      yajl_gen gen = ygenalloc();
  
      dump_bar_config(gen, barconfig);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_event("barconfig_update", I3_IPC_EVENT_BARCONFIG_UPDATE, (const char *)payload);
      y(free);
      setlocale(LC_NUMERIC, "");
  }
  
  /*
   * For the binding events, we send the serialized binding struct.
   */
  void ipc_send_binding_event(const char *event_type, Binding *bind) {
      DLOG("Issue IPC binding %s event (sym = %s, code = %d)\n", event_type, bind->symbol, bind->keycode);
  
      setlocale(LC_NUMERIC, "C");
  
      yajl_gen gen = ygenalloc();
  
      y(map_open);
  
      ystr("change");
      ystr(event_type);
  
      ystr("binding");
      dump_binding(gen, bind);
  
      y(map_close);
  
      const unsigned char *payload;
      ylength length;
      y(get_buf, &payload, &length);
  
      ipc_send_event("binding", I3_IPC_EVENT_BINDING, (const char *)payload);
  
      y(free);
      setlocale(LC_NUMERIC, "");
  }
  